The broad long term goal of this project is to empower women to protect themselves from HIV infection through the development of improved microbicides based on sustained release drug delivery. Each day 15,000 people are infected - a growing majority of them women. The development of an effective microbicide is thus of high programmatic relevance to the NIH as well as other world health organizations. There are more than 60 candidate agents identified, 18 of which have proceeded to clinical testing. One area that is receiving intense interest is the vaginal delivery of antiretroviral agents. A Phase I trial (HPTN 050), sponsored by the NICHD and other institutes of the NIH, showed tolerability of a gel formulation of tenofovir. A Phase II trial (HPTN 059) will further assess safety and tolerability in a larger sample for longer periods. There is currently no sustained release formulation for tenofovir in development. A vaginal ring formulation of the NNRTI T-120 is being actively investigated and shows great promise. A significant drawback of the silicone based delivery platform is that only very low solubility drugs can be delivered. We have developed a platform technology for the sustained release of a broad range of drugs by implantation;antiviral levels have been maintained for long periods. This technology lead to the ganciclovir intraocular implant: the Vitrasert., approved for the treatment of AIDS related CMV retinitis. We propose to utilize this platform to develop sustained release vaginal ring formulations for tenofovir. This platform could also be utilized for other antiretroviral agents, thus increasing the feasibility of a microbicide equivalent of HAART. PUBLIC HEALTH RELEVANCE: Each day 15,000 people are infected by HIV, the majority in sub-Saharan Africa and a growing percentage women infected though heterosexual sex. The broad long term goal of this project is to empower women to protect themselves from HIV infection through the development of an improved microbicide based on the sustained release drug delivery of the antiretroviral agent tenofovir.